Transition fault testability in bit parallel multipliers over GF(2m)

This paper presents a C-testable technique for detecting transition faults with 100% fault coverage in the polynomial basis (PB) bit parallel (BP) multiplier circuits over GF(2(m)). The proposed technique requires only 10 vectors, which is independent of multiplier size, at the cost of 6% (avg.) extra hardware and three control pins. The proposed constant test vectors which are sufficient to detect both the transition and stuck-at faults in the multiplier circuits can be derived directly without any requirement of an ATPG tool. As the GF(2(m)) multipliers have found critical applications in public key cryptography and need secure internal testing, a Built-in Self-Test (BIST) circuit is proposed for generating test patterns internally. This obviates the need of having three extra pins for the control inputs and also provides public-key security in cryptography. Area and delay of the testable circuit are analyzed using 0.18 mu CMOS technology library from UMC.